Rollback upgrade VCSA 6.0 to VCSA 6.7

Hello experts

I am a junior technician, and I have to make an upgrede of a Vmware Vcenter Appliance 6.0 to 6.7

I have been able to see the procedure on the internet, and it seems simple, I have two doubts:

1- When this process is done, is something modified in VCSA 6.0?
2- In case of failure, would it simply work as rollback to turn off VCSA 6.7 and turn on the old VCSA 6.0?

I want to be clear in case of error how to return to the original point, it is always necessary to make a snapshot or backuo with a third party tool, but I would like some expert of the web to confirm me.

Regards,